Working createOSXinstallPkg for macOS High Sierra 10.13

Just to get the word out. I have updated the createOSXinstallPkg to work with macOS High Sierra 10.13. Use of this should be the same as earlier versions. The original repository has been archived by the owner and I don't know how to get ahold of them to unlock it. I have made a fork of it, located at https://github.com/RedClawx/createOSXinstallPkg. If you're interested to see what was changed, just take a look at the commits.